AA 100 Lecture Notes - Lecture 1: Sulfur, Astronomical Unit, Magnesium

• School: CSU
• Department: Astronomy
• Course: AA 100
• Professor: Hardegree- Ullman, Emily E

Document Summary

First was the big bang, then hydrogen becoming helium, then the first galaxies, and finally, us! Within 5 minutes of the universe starting, 25% of hydrogen (had to) became helium. It took 1 billion years for gravity to bunch everything together and. A star like ours will poof out of existence and recycle the material into the universe. One bigger than ours will explode into a supernova and recycle the material into the universe. Eventually, all material is recycled and used again. Almost all helium that exists has been here since the big bang. You can"t make an element that is bigger than iron without energy. Those bigger elements must be made by supernovas. There are 8 elements that make up 95% of materials: If the big bang happened on new years (january 1): The first galaxies showed up in february. Solar system and basic life in september. Dinosaurs appear on december 29 and die on the 30th.